An electronic apparatus, for example, an image forming apparatus called MFP (Multi-Functional Peripheral) located on a network is connected to a router. The router is connected to a personal computer (a host apparatus) as a client or a server. Therefore, the MFP functions as a network printer or a scanner.
A client and an MFP that adopt a specific OS (operating system), for example, the Windows (trademark) series OS of Microsoft Corporation operate on a network that adopts IPv6 (Internet Protocol ver. 6) as a network interface.
A router corresponding to IPv6 allocates IP (Internet Protocol) addresses (stateless addresses) to the client and the MFP (stateless address autoconfiguration). The MFP acquires an IP address based upon a router advertisement (hereinafter referred to as RA) transmitted from the router in the network that adopts IPv6 as the network interface.
Therefore, when a setting on the router side is changed, the MFP connected to the network environment that adopts IPv6 as the network interface may become unrecognizable by the client or the server. When prefix information of the RA transmitted from the router is changed or when a term of validity of a prefix expires, the IP address is deleted regardless of convenience on the host side.
The router used in the network environment that adopts IPv6 as the network interface can automatically grant an IP address. The IP address automatically granted by the router is a stateless address. A system for granting the IP address is stateless address autoconfiguration. The automatically-granted IP address includes 128 bits in total, higher order 64 bits of which are defined by the router and lower order 64 bits of which are a MAC (Media Access Control) address.
For example, JP-A-2003-134116 (Patent Document 1) discloses that, in a network that adopts a DNS (Domain Name System), inconsistency and mismatch of address information is prevented from occurring between a server and an image processing apparatus that is turned on and off independently from the server.
However, Patent Document 1 does not indicate expansion to the network environment that adopts IPv6 as the network interface.